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Date:   Mon, 26 Aug 2019 09:20:55 -0300
From:   Jason Gunthorpe <jgg@ziepe.ca>
To:     Souptick Joarder <jrdr.linux@gmail.com>
Cc:     leon@kernel.org, Doug Ledford <dledford@redhat.com>,
        linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
        Matthew Wilcox <willy@infradead.org>
Subject: Re: [PATCH] IB/mlx5: Convert to use vm_map_pages_zero()
Message-ID: <20190826122055.GA27349@ziepe.ca>
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On Mon, Aug 26, 2019 at 01:32:09AM +0530, Souptick Joarder wrote:
> On Mon, Aug 26, 2019 at 1:13 AM Jason Gunthorpe <jgg@ziepe.ca> wrote:
> >
> > On Sun, Aug 25, 2019 at 11:37:27AM +0530, Souptick Joarder wrote:
> > > First, length passed to mmap is checked explicitly against
> > > PAGE_SIZE.
> > >
> > > Second, if vma->vm_pgoff is passed as non zero, it would return
> > > error. It appears like driver is expecting vma->vm_pgoff to
> > > be passed as 0 always.
> >
> > ? pg_off is not zero
> 
> Sorry, I mean, driver has a check against non zero to return error -EOPNOTSUPP
> which means in true scenario driver is expecting vma->vm_pgoff should be passed
> as 0.

get_index is masking vm_pgoff, it is not 0

Jason